A baseline tool for predicting response to peginterferon alfa-2a in HBeAg-positive patients with chronic hepatitis B

BACKGROUND

Peginterferon induces off-treatment responses in approximately one-third of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B.

AIM

To develop an easy-to-use baseline prediction score to identify hepatitis B virus (HBV) genotype B-/C-infected HBeAg-positive Asian patients likely to respond to peginterferon alfa-2a.

METHODS

Generalised additive models, multiple logistic regression (MLR) analysis and internal validation methods were applied to data from 647 HBeAg-positive patients from China, Hong Kong and Taiwan to develop a scoring system to predict response 24 weeks after completing a 48-week course of peginterferon alfa-2a.

RESULTS

Five baseline factors (age, sex, alanine aminotransferase ratio, hepatitis B surface antigen (HBsAg) level and HBV DNA level) were retained in the final MLR for HBeAg seroconversion and used to develop a scoring system from 0 to 7. Among patients with scores of 0-1, 2-3, 4 or ≥5, HBeAg seroconversion was achieved in 6.4% (6/94), 23.0% (61/265), 36.4% (67/184) and 54.8% (57/104), respectively, and a combined response (HBeAg seroconversion plus HBV DNA <2000 IU/mL) in 5.3% (5/94), 12.8% (34/265), 25.0% (46/184) and 36.5% (38/104), respectively. Among patients with scores of 0-1, 2-3, 4 or ≥5, 57.0% (53/93), 12.3% (31/253), 3.4% (6/178) and 1.0% (1/100) had HBsAg ≥20 000 IU/mL at treatment Week 12; only 3/91 (3.3%) with HBsAg ≥20 000 IU/mL experienced a combined response at 24 weeks post-treatment (negative predictive value = 97% [88/91]).

CONCLUSION

A pre-treatment scoring system using readily available baseline characteristics identifies HBeAg-positive Asian patients likely to experience sustained HBeAg seroconversion after treatment with peginterferon alfa-2a.

Protective role of vitamin C in diazepam-induced apoptosis in rat thymocytes

Diazepam, a peripheral-type benzodiazepine receptor ligand, is widely used as a therapeutic agent. On the other hand, peripheral-type benzodiazepines have been shown to induce apoptosis in different immune cell types. In this study, we examined the possible protective role of vitamin C in diazepam-induced apoptosis and evaluated the cellular content of glutathione during this process. Rat thymocytes were incubated for 24 hours with diazepam and increasing concentrations of vitamin C or with diazepam alone. The exposure to diazepam resulted in an increase in apoptotic cell death and decrease in glutathione content in rat thymocytes. Vitamin C was effective in ameliorating the effect of diazepam in rat thymocytes by decreasing the proportion of apoptotic cells and increasing the cellular content of glutathione. These results suggest that vitamin C reduced the diazepam-induced apoptosis in rat thymocytes by restoring the cellular content of glutathione, which may be useful in preventing the diazepam-induced immunosupression (Tab. 1, Fig. 1, Ref. 31).

Circulating nucleic acids in type 1 diabetes may modulate the thymocyte turnover rate

The autoimmunity of type 1 diabetes is associated with T-cell hyperactivity. Current study was designed to examine the effect of circulating ribonucleic acids (RNAs), isolated from type 1 diabetic patients on proliferative, apoptotic and inflammatory potential of rat thymocytes. Rat thymocytes were assayed for proliferating nuclear cell antigen (PCNA), Bcl-2, Bax and NF-κB level, using the flow cytometric and fluorometric assays. Cells were allocated into groups, treated with RNAs purified from plasma of juvenile diabetics, adult type 1 diabetic patients, control healthy children, healthy adult persons, nucleic acids and polynucleotide standards (RNA, polyC, PolyA, PolyIC, and CpG). The upregulation of PCNA and Bcl-2 protein and downregulation of Bax protein and NF-κB was shown when the thymocytes where incubated with RNA purified from plasma of juvenile type 1 diabetic patients. The dysregulation of inflammatory cascade and central tolerance may be a defect in autoimmune diseases related to innate immunity leading to corresponding alteration in adaptive immune response.

The role of ascorbic acid and monosodium glutamate in thymocyte apoptosis

The studies on experimental animals have confirmed toxic effect of monosodium glutamate in different organs, mainly manifested by increased oxidative stress and cytotoxicity, strongly correlated with numerous diseases. Continuous intake of this flavor enhancer in modern nutrition also resulted with toxic effects on human health, known as Chinese restaurant syndrome. The reference data about influence of monosodium glutamate on the cells of the immune system or primary immune organs and possible protective effects of specific antioxidants are still largely unknown. This review summarizes recently known facts about the role of monosodium glutamate in the cells of the immune system, especially in thymocytes. Also, in this review many new data on positive effects of ascorbic acid on immune system and the mechanisms of its protective influence on thymocytes are discussed (Tab. 1, Ref. 52).

Low-dose cyclosporine A therapy increases the regulatory T cell population in patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a T cell dependent chronic relapsing inflammatory skin disorder successfully treated with cyclosporine A (CsA). Clinical observations indicate that even low-dose CsA therapy is successful in severely affected AD patients. We studied the impact of low-dose CsA therapy on the ability of T helper cells to be activated, and examined whether regulatory T (Treg) cells are increased in these patients.

METHODS

Peripheral T cells were activated in a whole blood sample and interleukin-2 producing cells were measured by intracellular cytokine staining. Regulatory T cells were analyzed by intracellular FoxP3 staining. Regulatory T cells (CD4(+)CD25(+)CD127(low)) and effector T cells (CD4(+)CD25(-)CD127(+)) were sorted by flow cytometry and used for suppression assays.

RESULTS

A group of AD patients treated with low-dose CsA had a significantly larger Treg cell population than a healthy control subject group. In individual patients, onset of low-dose CsA therapy reduced the ability of T cells to be activated to 42 +/- 18% (P < 0.005) and significantly increased Treg cells, both in absolute numbers (1.6-fold change) and frequencies (1.7-fold change). Treg cells from AD patients showed similar suppressive capacities as Treg cells from healthy donors. Furthermore, Treg cells from AD patients had skin homing properties.

CONCLUSION

Our results indicate that the therapeutic effect of low-dose CsA therapy in AD patients might be not only mediated by the inhibition of T cell hyperactivity but also by an increased population of Treg cells.

Ascorbic acid modulates monosodium glutamate induced cytotoxicity in rat thymus

BACKGROUND

Monosodium glutamate (MSG) is a commonly used flavor enhancer in modern nutrition. It has been shown that administration of MSG induces toxic effects in various regions of brain, thymus, liver and kidney. Also, it is well-documented that Vitamin C (ascorbic acid) has a protective role in MSG-induced cytotoxicity in rat liver, kidney and various brain regions, but has not been studied in thymus.

OBJECTIVES

In the present study, we examined the possible protective role of Vitamin C in MSG-induced cytotoxicity in adult (Kindly indicate the strain of rat) rat thymus.

MATERIAL AND METHODS

MSG was administrated intraperitoneally (4 mg/g of body weight), with or without Vitamin C (500 mg/kg of body weight), for six consecutive days. Animals were sacrificed at 1st, 7th and 14th day of last MSG dose.

RESULTS

This study demonstrates that MSG administration in animals significantly decreases cell viability with significant down-regulation of Bcl-2 protein, while Bax protein expression was not significantly changed in rat thymocytes. Vitamin C was effective in ameliorating the effect of MSG in rat thymocytes by increasing the proportion of viable cells and up-regulating the expression of Bcl-2 protein in rat thymocytes.

CONCLUSION

These results suggest that the treatment with Vitamin C may prevent the MSG-induced cytotoxicity in rat thymocytes by up-regulating Bcl-2 protein expression resulting in a change in Bcl-2/Bax protein ratio (Tab. 1, Fig. 1, Ref. 32). Full Text (Free, PDF) www.bmj.sk.

Follicular dendritic cell sarcoma in the lymph nodes of the neck

Follicular dendritic cell sarcoma (FDCS) is a rare tumor, derived from antigen-presenting cells that normally form meshworks in lymphoid follicles. FDCS in general recapitulate the immunophenotypic profile of follicular dendritic cells (FDCs). This tumor affects mainly the lymph nodes, but may arise at a variety of extranodal sites in about one third of cases. We present a case of FDCS in a 52-year-old woman with left neck mass. Histologically, the tumor was composed of oval-to-spindle cells arranged in a fascicular and storiform pattern. Immunohistochemically, the tumor cells were positive for CD21, CD35, and to a lesser extent for EMA and vimentin (Fig. 3, Ref. 14). Full Text (Free, PDF) www.bmj.sk.

Modulatory effect of monosodium glutamate on rat thymocyte proliferation and apoptosis

BACKGROUND

Monosodium glutamate (MSG) is the sodium salt of glutamic acid, widely spread in modern nutrition. Numerous recent studies have shown the existence of glutamic receptors on different nonneuronal cells, which among others also include lymphocytes and thymocytes.

OBJECTIVES

The current study was designed to evaluate the prolonged effect of MSG on rat thymocyte proliferation, apoptosis and expression of two apoptosis related proteins, Bel-2 and Bax.

MATERIAL AND METHODS

Wistar rats (male) were exposed to monosodium glutamate (MSG) (4 mg/g body wt, i.p.) for 6 consecutive days and sacrificed on 30th and 45th day after last MSG dose. Thymocyte proliferation was evaluated by measuring the expression of proliferating cell nuclear antigen by flow cytometry. Apoptosis was detected using the Annexin V-FITC/PI apoptosis detection kit and cells were analyzed using a flow cytometer. Expression of Bcl-2 and Bax proteins were determined with flow cytometry using respective monoclonal antibodies.

RESULTS

The current study results demonstrate that MSG significantly decreased thymocyte proliferation (p < 0.001) induced by ConA and increased apoptosis rate (p < 0.001) of the cells during examination period. MSG treatment induced down regulation of Bcl-2 protein while Bax protein levels were not significantly changed.

CONCLUSION

These results indicate that MSG significantly modulates thymocyte proliferation by modulating the apoptosis rate of the cells. The temporal profile of Bcl-2 and Bax expression, after MSG treatment, suggest that down regulation of Bcl-2 protein and resulting change of Bcl-2/Bax protein ratio may be an important event in thymocyte apoptosis, triggered by MSG (Tab. 1, Fig. 3, Ref. 36).